1. Field of the Invention
The invention relates in general to a method for adjusting the uniformity of a panel and associated display controller, and more particularly, to a method for adjusting brightness and uniformity of colors displayed on a panel and associated display controller.
2. Description of the Related Art
Display panels, e.g., color liquid crystal display (LCD) panels for monitors and televisions, being capable of presenting diversified multimedia information, are prevalent in the modern information society.
A panel comprises a plurality of pixels that are driven and controlled to display by a display controller (e.g., a control chip). The display controller receives from a signal source a video stream comprising a series of input values, each corresponding to a particular pixel. The display controller then controls the pixels to display corresponding colors according to the input values of the pixels. For example, each of the input value (r_in, g_in, b_in) comprises three input components, a red component r_in, a green component g_in, and a blue component b_in. A value of each of the input components is between a bottom component value 0 and a top component value (J-1) and may thus have J number of possible candidate values. That is to say, based on various combinations of input components, the input value (r_in, g_in, b_in) may have J*J*J number of possible candidate values for respectively describing J*J*J number of colors of the pixels displayed on the display.
However, due to various factors associated with a panel, e.g., unevenness of backlight, assembly errors, and different degrees of manufacturing drifts on pixels at different positions, colors displayed by pixels at different positions of the panel may still be different even when a same input value is inputted to all of the pixels of the same panel. As a result, the panel may fail to consistently display a uniform color at different regions of the panel.
The uniformity of colors displayed on a panel may be measured by a color meter. For example, a panel may be divided into a plurality of blocks, e.g., 9 or 25 blocks, and colors displayed at positions of the blocks are respectively measured by the color meter to obtain a display value (X, Y, Z) for the block. The display value comprises three display components X, Y, and Z, each of which has three primary color components R, G, and B. Out of the three display components X, Y, and Z, only the display component Y is associated with luma and is regarded as a main display component, and the display components X and Z are regarded as two auxiliary display components. By combining the display components X, Y, and Z, a color characteristic value, e.g., a color temperature or chroma, may be calculated. When each of the pixels receives a same input value, a color output uniformity is then quantitatively estimated by comparing brightness and/or color characteristic values of a panel. More specifically, uniformity reduces as differences between brightness and/or color characteristic values of different blocks get larger.
A panel with unsatisfactory uniformity is incapable of correctly displaying video to significantly impose desirable effects on a quality presented by the panel.